Swash plate pump adjusting means



Feb 15,1944 i' J. T. GONDEK 2,341,768 swAsH PLATE PUMP ADJUSTING MEANS Filed March 24, 1942 2 Sheets-Sheet l .3l I Z4 FLgl.

z/ fz l i s) e) J I Z/ v /f /4 l r I -6 6 l /e /l l l al /Z l /f M I I' y 'y H Inventar 34a] 3 7 udfafyfl( 'tftor-neg.

larly to a pump of the swash plate type.

Patented Feb. 15, 1944 SWASH PLATE PUMP ADJUSTING MEANS John Thomas Gondek, Minneapolis, Minn., assignor to Northern Pump Company, Minneapolis, Minn., a corporation of Minnesota f Application March 24, 1942, Serial No. 436,025

3 Claims.

This invention relates to a pump and particu- Such pumps have a tilting plate in which the swash plate is rotatable and the said tilting plate is swingaole about an axis and movable to diierent positions to vary the stroke of said pump.

It is an object of this invention to provide a novel, simple and eiiicient means for swinging the tilting plate to vary the stroke of the pump.

It is a further object of the invention to provide a novel, simple and efficient means for swinging said tilting plate, which means is quite rugged'and includes a member rigidly secured to said tilting plate having a head projecting therefrom, means embracing said headand a member movable at right angles to the aXis about which the tilting plate swings in which said means is movable. y

It is more specifically an object of the invention to provide means for swinging said tilting plate about an axis comprising a member secured to said plate and having a head projecting therefrom having a cylindrical portion, a second member movable rectilinearly at right angles to said axis having a portion with a passage extending at right angles therethrough and a block at each side of said head closely embracing the same, said blocks fitting in and being slidable in said passage when said second member is moved rectilinearly to swing said tilting plate, said head having angular movement in said blocks.

These and other objects and advantages of the invention will be fully set forth in the following description made in connection with the accompanying drawings in which like reference characters refer to similar parts throughout the several views and in which:

Fig. 1 is a partial View of certain parts of the invention;

Fig, 2 is a vertical section taken on line 2-2 of Fig. 1 as indicated by the arrows and shown on a reduced scale;

Fig. 3 is a partial View of certain parts of the invention; l

Fig. 4 is a vertical section taken on line 4-4 of Fig. 3 as indicated by the arrows shown on an enlarged scale;

Fig. 5 is a vertical section taken on line 5-5 of Fig. 4 as indicated by the arrows also shown on an enlarged scale; and

Fig. 6 is a partial section taken on line 6-6 of Fig. 1 as indicated by the arrows.

Referring to the drawings a portion of a pump of the swash plate type is shown in which it will only be necessary to consider the casing l0 which is of rectangular shape in vertical cross section, the same having an end plate illa secured in place by headed and nutted bolts l extending longitudinally of said frame. Said frame has at the sides thereof secured by suitable bolts l2 driven bearings i3. Journalled in bearings i3 are the trunnions Uta. of a tilting plate it, said plate being cscillatable about trunnions ita. The driving shaft l5 of the pump is shown in section inFig. 2.

Secured to the rear of plate i4 at one side of shaft l5 is a bracket I6. While this bracket could be variously made, in the embodiment of the in vention illustrated it is shown as having a ange Ia of general rectangular form with reentrant recesses at opposite ends thereof, said ange being received in a recess ith formed in plate lll. The bottom of ange ia engages the plate It and is secured in place by a plurality of headed screws Il. Bracket I6 also has a central cylindrical stem Ilb which lits in a bore formed in plate lll. Bracket l has a head lc which projects outwardly from ange Ita, said head having semi-cylindrical surfaces ld at opposite sides thereof. Blocks I8 are formed to t against the semi-cylindrical surfaces it at their inner sides and at their opposite sides said blocks have semi-cylindrical surfaces l8a tting in a passage 19a formed in a yoke ith which forms a portion of a member i9. It will be seen that passage la is of general elliptical or oblong form having semi-cylindrical ends and that the nat sides of head l6c are spaced slightly from the sides of said passage. Head lc is shown as having a central cylindrical opening I6@ therethrough. Member I9 is in the form of a stem or shaft and at one end is threaded to form a screw portion c. A nut 26 embraces screw i90 and has a cylindrical portion Zlla journalled in spaced ball bearings 2i. Ball bearings 2l are supported in frame Ill and in a ring 22 held in place by a cylindrical cap or casing 23 secured to casing Il) by the headed bolts M. One of said bearings is also supported on a flange 20h of the nut 20. A nut 26 is also threaded on the outei` portion of nut 20, the same engaging a collar '2l engaging the casing or race of one of the bearings 2i. Nut 26 is provided with a locking means or washer 28. It will be seen that the outer portion of nut 20 is bored to form a cylindrical chamber surrounding the end portion of screw lilo and being rotatable in a stuing gland 30 which fits in casing 23, the same being held and adjusted by the headed bolts 3|. Packing material 32 surrounds said cylindrical portion of nut 20 and is engaged by the gland 30. The outer portion of nut 20 is provided with a threaded stem 20c which will receive some means for turning said nut. The other end of member I9 is formed as a guide 19d having a plurality of ribs or keys thereon fitting in and movable in grooves or keyways in a member 34 tting in one side of casing l and having a flange 34a secured to said ycasing by the headed screws 35. Member 34 is provided with a cap 36 secured to its end portion by the headed screws 3l.

When it is desired to change the position of tilting plate I4 to change the stroke of the pump member I9 will be moved longitudinally. Whiler this member could be variously moved, in the embodiment of the invention illustrated it will be moved by some means engaging the stem 2llcy and rotating the nut 20. Nut 20 will be easily rotated and this will cause longitudinal movement of screw |60. It will be seen that member I9 is confined to non-rotative rectilinear movement by the guide head or portion l9d. When member I9 is thus rectilinearly moved the yoke portion Ito thereof will be moved as will the blocks I8, These blocks will exert movement of head lc and this will result in tilting plate I4 about the axis of trunnions ida. It will be seen that head lGc can have oscillating or angular movement relatively to the blocks i3. These blocks can also have movement in the p-assage |90., thus moving at right angles to the axis of member I9. The angular movement of bracket I6 and its head |60 is thus taken care of by relative movement between said head, blocks I8 and the yoke ISb. The plate can thus be easily moved and easily and quickly moved through small distances.

The present structure is an improvement upon that disclosed and claimed in the co-pending application of John B. Hawley Jr., S. N. 375,742, led January 24, 1941, on Hydraulic pump construction. The present structure is very rugged, durable and comprises few parts. The pumps of the type herein involved are used to create heavy pressure. As the cylinder barrel revolves the cylinders and pistons shift from the inlet tothe outlet side of the pump or might be said to commutate from the inlet port to the outlet port. This causes a great impact on the pistons, cylinder barrel and other parts which are thus put under great stress and take, so to speak, quite a pounding. This shock or stress is transmitted to the other parts andthe adjusting mechanism for the tilting plate also receives said shock and stress or a large part thereof- The more rugged and simple the adjusting mechanism can be therefore, the better it is. The present structure gives all the necessary movements to permit the tilting action of the tilting plate and yet is at the same time very rugged and durable.

From the above description it will be seen that I have provided a very novel, simple and efficient adjusting mechanism for the tilting plateof a swash plate pump. The invention has been Worked out from long experience andis a very practical one. rIhe device has been amply demonstrated in actual'practice and is beingputinto commercial production.

It will, oi course, be understood that .various changes may be made in the form, details, arrangement and proportions of the parts, without departing from the scope of applicants invention, which generally stated, consists in a device capable of carrying out the objects above set forth, in the parts and combinations of parts disclosed and defined in the appended claims.

What is claimed is: k

1. In a pump of the swash plate type having a casing and a tilting plate swingable in said casing about an axis to vary the stroke of the pump, a shaft member mounted for endwise reciprocation at its ends in said casing and extending substantially at right angles to, and being offset from the axis of said tilting plate, means for restraining said shaft against rotation, said shaft having an intermediate yoke disposed adjacent said tilting plate; means for reciprocating said shaft; and means for transmitting reciprocations of said shaft to said plate, for varying the stroke of saidk pump, comprising a member secured to said plate and having a head projecting into said yoke, the head of said member having a cylindrical external surface whose axis is disposedrat right angles to saidy shaft and parallel tothe axis of said tilting plate, a slide element disposed either side of said head and having internal cylindrical surfaces accurately engaging the cylindrical surface of said head, and adapted to coact solely in rocking engagement therewith, s aid slide elements also having external cylindrical surfaces coacting in rocking engagement with internal cylindrical surfaces formed in the ends of said yoke, the axes'of said internal and external cylindrical surfaces of said elements being disposed at right angles to each other, and said elements being freely slidable in a direction normal to said shaft, whereby they may undergo a cross-head motion with respect thereto and yet be maintained in rocking engagement with said head.

2. The mechanism defined in claim 1', wherein said means for restraining said shaft against rotation comprises an internally splined sleeve extending into saidv` easing and slidably coacting with a setV of splines provided'on said shaft, and means for rigidly securing said sleeve toY a wall of said' casing.

3` The mechanism defined in claim 1, wherein said means for reciprocating said shaft comprises a cage bolted over an opening in saidv casing; an apertured member securedbetween said cage and said wall; a sleeve projecting through said'member into` said opening andmounted for rotation in thrust bearings located either side of said member; means on said sleeve cooperating with said bearings for precluding endwise movement of said sleeve, said sleeve surrounding one en'd' of said shaft and being threadedly connected thereto, said sleeve projecting outwardly through'said cage and having means located externally of lthe latter for imparting rotative adjusting eiortsto said sleeve.

JOHN THOMAS GONDEK. 

